This section is intended to introduce various aspects of the art, which may be associated with embodiments of the disclosed techniques. This discussion is believed to assist in providing a framework to facilitate a better understanding of particular aspects of the disclosed techniques. Accordingly, it should be understood that this section is to be read in this light, and not necessarily as admissions of prior art.
Three-dimensional (3D) model construction and visualization have been widely accepted by numerous disciplines as a mechanism for analyzing, communicating, and comprehending complex 3D relationships. Examples of structures that can be subjected to 3D analysis include the earth's subsurface, facility designs and the human body.
With respect to providing visualizations of data regarding a 3D earth model, the current practices generally relate to processing and visualizing the geological data types such as seismic volumes, a geo-modeling grid, fault surfaces, horizon grids, well data and the like. In addition, it may be desirable to visually represent engineering and geoscience data types, which may be point or non-spatial data. Examples of such data types include drilling information, daily/monthly production data, geochemical or geomechanical analysis results, production measurements or the like.
The addition of time variability into the modeling of earth model data presents a challenging technical problem. A data set that includes 3D earth model data as well as time variability data may be referred to as four-dimensional (4D) data. Known modeling techniques do not include the ability to provide integrated visualizations inclusive of a broad range of earth model data types in 4D visual form.
One method of providing data for visualization includes the use of a numerical technique known as enriched finite element modeling (EFEM). EFEM is a modeling technique that allows effective analysis of localized features such as cracks, faults, fractures or the like that are not efficiently resolved by mesh refinement. In EFEM, a discontinuous basis function may be added to standard polynomial basis functions to allow modeling of discontinuous local events. The modeling of local events may thus be performed without the need to redefine the entire finite element mesh.
One step in the EFEM formulation requires the integration over a cell intersected by discontinuous subsurface features of interest. One method of doing that is to partition the cell according to the subsurface features and then perform integration piece by piece. The cell partition used for integration can also aid visualization. This is because subsurface features usually bring discontinuity in to the solution. To display such a discontinuity, the region on the two sides of the feature needs to be represented differently (for example, with different colors). The existing cell partition used for integration can effectively serve this purpose.
No existing visualization toolkits have been optimized to produce visualizations of the results of EFEM techniques. There are several characteristics of EFEM analysis that contribute to difficulties in providing visualizations. For example, EFEM is typically performed on very large models, such as models having millions of cells. In addition, it is frequently desirable to analyze a large number of time steps, and cells may be partitioned over time. Property definitions may change and span across multiple time steps. Also, the rendering of discontinuities may be made difficult because of the presence of hanging nodes.
Known visualization programs that support any changes to the mesh over time represent the changing mesh as discrete instances, requiring redefinition of the entire mesh at each time step. For example, one known visualization program allows different portions of a model to be activated at different times. Moreover, portions can be loaded to represent all time steps and activated in sequence to produce the effect of showing a mesh that is changing in time. Each portion of the model is redefined and stored independently and there is no attempt to share data between time steps.
U.S. Patent Application Publication No. 20080312887 relates to a software program that supports user directed grid enrichment and flow solution adaptive grid refinement. User selectable options such as the choice of functions, the choice of thresholds, etc., other than a pre-marked cell list, can be entered on a command line. The ease of application is an asset for flow physics research and preliminary design computational fluid dynamics analysis where fast grid modification is often needed to deal with unanticipated development of flow details.
One known visualization approach provides the ability to model dynamic migration in a subsurface region by simulating changes in property values over time. In addition, this application provides simulation of model geometry changes over time. The time changing model geometries also allow for time changing surfaces and pointsets. However, this known application only allows the specification of model geometry, not the specification of associated surfaces and pointsets derived from the model geometry. Moreover, the surfaces and pointsets of the known application cannot be modified or created separately from the model geometry. Further, the known application only allows definition of the model geometry at an initial time. The user is not permitted to make further changes to the model geometry after it is defined. A method that effectively incorporates time-variability into the presentation of visual images of a structure such as a subsurface region is desirable.
U.S. Patent Application Publication No. 20080262809 relates to a method and system for modeling petroleum migration. This application purports to describe a method for modeling the migration of reactant in a subsurface petroleum system. The method comprises in part generating a mesh for an area of the petroleum system. The mesh comprises a plurality of nodes, with each node representing a point in space in the area. The method also comprises calculating one or more variables representing one or more physical characteristics at each node in the area and determining the migration of reactant in the petroleum system based on the one or more variables. The method is alleged to be able to process multiple reactant phases and non-static meshes.